High speed loom



June 24, 1969 WILBE Em 3,451,438

HIGH SPEED LOOM Filed May 1. 1967 sheet of 5 2o L dwf.....mlllflUmll 24,/Si F IG 42 40 Q Il!" 1- Il "r la"r INVENTORS.

o EON G. WILBE ALBERT szczUR WILUAM J. STEPHENS ATTORNEYS June 24, 19691 G. WTLDE ET AL HIGH SPEED LOOM Filed May l, 1967 Sheet 2 of 5 78.) 6874\ 78? 30 /f JT\ 72' x. M .)iul 28 V\7O 76f C 86 88 90 il LOW SPEEDCLOCK l DOWN Y TAR 482 STOP GATE UP COUNTER Y saz HIGH SPEED CLOCK F IG.3

INVENTORS. LEON G. WILDE ALBERT SZCZUR WILLIAM L!A STEPHENS ATTORNEYSJune 24, 1969 L. G. WILDE ET AL 3,451,438

HIGH SPEED LOOM Filed May 1, 1967 sheet 3 of .5

POWER |20 *Y SUPPLY f, T

|48 I 2 DOFFER ACTUATOR INVENTORS. LEON G. WILDE ALBERT SZCZUR WILLIAMJ. STEPHENS F|G.8 WWW/m20@- ATTORNEYS June 24, 1969 L. G. WILDE ET ALHIGH SPEED LOOMr Sheet Filed May l, 1967 FIG. IO

INVENTORS. LEON G. WILDE A ALBERT SZCZUR WILLIAM J. STEPHENS ATTORNEYS yJune 24, 1969 L W|LDE ET AL 3,451,438

HIGH SPEED LOOM Filed May 1. 1%? sheet 5 of 5 (qu) LO Il' O Ui O V v LL].3 C\1 q' II LO v sf.

lNvENToRs. (D LEON s. WILDE ALBERT szCzuR I L. BY WILLIAM J. STEPHENSATTORNEYS United States Patent C) 3,451,438 HIGH SPEED LOOM Leon G.Wilde, Andover, Albert Szczur, New Bedford,

and William J. Stephens, Bedford, Mass., assignors to Z and DIndustries, Inc., Woburn, Mass., a corporation of Massachusetts FiledMay 1, 1967, Ser. No. 634,978 Int. Cl. D03d 49/54 U.S. Cl. 139-187 9Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION (l) Fieldof the invention This invention relates generally to looms and moreparticularly is directed towards automatic high speed looms andassociated components thereof.

(2) Background of the invention Present day looms are mechanicallycomplex, automatic machines in which a bobbin-carrying shuttle ispropelled back and forth through a shed of warp threads. The shuttlelays down a ller thread or pick on each pass and after each pick thereed beats the filler against the formed fabric and the warp threadsalternate positions to form the shed for the next pick. The shuttle ispropelled 'back and forth at a rather high rate of speed by means ofpicker sticks which, at the proper timed moment, are actuated tO drivethe shuttle across the lay through the shed. A shuttle box is locatedeach side of the loom in position to catch the shuttle after it passesthrough the shed. The shuttle box is provided with a braking mechanismintended to grab the shuttle at the end of its flight. Numerous controlcomponents have been added and these include a trip mechanism in theevent that the shuttle is not properly seated in the shuttle box, athread depletion detector for initiating the dofling mechanism whichreplaces the empty bobbin with a full bo'bbin and mechanisms fordetecting broken weft threads.

While looms that are properly adjusted operate more or lesssatisfactorily for a time, they have a great tendency to work themselvesout of adjustment primarily due to the mechanical complexity of thevarious control mechanisms and the constant vibration of the loom whenoperating. Looms thus require frequent readjustment otherwise the loomwill shut itself down when there is a malfunction and also when there isa false indication of a malfunction. To the weaver this istime-consuming and bothersome since it necessitates correcting themalfunction and restarting the machine. For the mill the starting andstopping of the machine is undesirable since it represents loss inproduction time and with certain materials, an interruption in theweaving process produces an objectionable mark on the nished fabric.

ICC

Accordingly it is a general object of the present invention to provideimprovements in high speed looms. More specifically it is an object ofthe invention to provide an automatic loom capable of increased speedand reliability coupled with reduced waste and of generally moreefficient operation.

SUMMARY OF THE INVENTION This invention features an automatic loomcontrol system and associated components including a shuttle positioningsystem adapted to stop and precisely position the shuttle in itsappropriate box each time it has completed a pick of the warp shed. Theshuttle positioning system includes a photo-electric device at theentrance of each shuttle box. Each device is operatively connectedthrough a time delay to an actuating mechanism adapted to brake theshuttle in the shuttle box at a precisely determined and repeatableposition. Logic circuitry responsive to the electric eyes is providedfor stopping the loom in the event of a malfunction or in the event thatthe shuttle is not properly positioned. This invention also features animproved system for detecting the depletion of weft thread on thebob'bin and for actuating the doing mechanism with a minimum amount ofthread Waste.

This invention also includes an improved broken thread p detectorcomprising a spring biased nger adapted to bear against the ller threadafter it is deposited in the shed by the shuttle. The finger controls ashuttle between a photocell and a light source whereby a signal isproduced indicating the condition of the thread.

As a further feature of the invention, novel means are provided fordisengaging the drive clutch to the loom prior to stopping the movementof the lay. This reduces the kinetic energy of the loom which isoperating at a high speed.

Yet another feature of this invention includes the employment of powercylinders under 'the control of timing systems for operating the loomharnesses.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of ashuttle box control mechanism made according to the invention,

FIG. 2 is a schematic diagram, in a simplified form, of the shuttle boxcontrol system,

FIG. 3 is a block diagram of a variable time delay circuit for theshuttle box control, p

` FIG. 4 is a view in perspective of a trip mechanism for actuating theloom stop mechanism,

FIG. 5 is a somewhat schematic diagram of a thread depletion system madeaccording to the invention,

FIGS. 6, 7 and 8 are similar views showing modifications of the F IG. 5system,

FIG. 9 is a view in perspective of a broken filler thread detectingdevice made according to the invention,

FIG. 10 is a view in perspective of a power cylinder system foroperating the loom harnesses, and

FIG. 11 is a schematic diagram of the logical circuitry for the variouscontrol units.

DESCRIPTION OF THE PREFERRED EMBODIMENTS By way of introduction a briefdescn'ption of the construction and operation of a loom will be given.The principle on which the loom is based is that of manipulating twoseries of yarns namely, the Warp and the weft, so that the two are wovenas the Warp threads are drawn slowly through the loom. The warp threadsare separated frequently and the liller thread, which is contained in ashuttle, is propelled through the transverse opening called the shedformed by the separated warp threads. The warp threads are crossed aftereach pick of filling is inserted and pushed into place by a comb-likestructure called the reed so as to force the last pick into placeagainst the previously woven material.

In making the cloth, sorne of the warp threads must be raised and otherslowered to produce the triangular space through which the ller ispassed. This space is called the shed and through it the shuttlecontaining `the filler thread on a replaceable bobbin is thrown fromside to side.

The throwing across of the filler thread is known as picking. Theshuttle being thrown from one side of the loom to the other, leaves thefiller thread some distance from the edge or fell of the cloth. It istherefore necessary to push it forward to the cloth, that is to the pickthat has been previously pushed in to form the fabric.

The shuttle is a hollow boat-shaped receptacle, intended to carry thefiller thread wound on a bobbin and leave a trail of yarn behind it asit is thrown through the shed of warp yarns. When the supply of yarn onthe bobbin, carried by the shuttle, is almost depleted, a doiiingmechanism is actuated which automatically replaces the nearly emptybobbin with one that is full and the weaving is continued withoutinterruption.

The shuttle is thrown between two mechanisms known as shuttle boxes, onelocated at each end of a movable beam known as the lay. A picker stickextends into each shuttle box and serves as the means for driving theshuttle from one box to the other. The box guides the shut-tle as it isthrown across the lay and also serves as a receptacle for the shuttle,gradually retarding its motion as it enters the box at the end of itspass. In practice, one of the sides of the shuttle box is pivoted to actas a brake which is slightly curved inward so that it projects into theshuttle box and presses against the side of the shuttle as it enters thebox. Pressure is applied to the brake, which is known as a binder, bymeans of a finger and spring device mounted on a protector rod, the ngerbeing kept pressed against the binder by means of the spring.

One of the main problems in automatic looms involves the control of theshuttle. Rather frequently the shuttle will not come to rest in theshuttle box at the same spot each cycle. If the shuttle does not stop atthe same position, various malfunctions can occur. For example, if theshuttle does not go far enough into the shuttle box it will not be inthe proper position to be driven by the picker stick for the returnmovement. Also the thread depletion mechanism will not contact thebobbin at the proper point and may indicate an empty bobbin when in factthe bobbin may still have a substantial supply of weft thread left onit. This will actuate the dotiing mechanism and result in substantialwaste of unused weft thread. If the shuttle goes too far into theshuttle box it may bounce against the driving end of the picker stickand rebound, again coming to rest out of position to be properly drivenby the picker stick. In any event, present mechanisms for operating theshuttle box requires frequent adjustment for proper operation and alsoplace a limit on the speed at which the loom can be operated.

Referring now to FIG. l there is shown a perspective view of a shuttlebox control mechanism, the shuttle box being generally indicated by thereference character and mounted on the end of a lay 12. For purposes ofdiscussion and illustration only one shuttle box is shown and describedand it will be understood that a similar shuttle box is located on theopposite end of the lay and functions in the same fashion.

In FIG. 1 there is shown a portion of woven cloth web 14 coming from theloom with warp threads 16 and 18 forming a triangular shed through whichthe shuttle is propelled. The shed is formed by reciprocating harnessesto be described more fully in connection with FIG. 10. A reed 22 ismounted on the lay 12 and cyclically advances the filling thread or picktowards the woven edge or fell 24 of the cloth 14.

The shuttle box 10 is slotted at 26 to receive the upper end of a pickerstick 28. A picker 30 is mounted on the upper end of the picker stickand is formed with a conical socket on the inner face thereof to receivethe pointed end of the shuttle. The picker stick is pivoted clockwiseunder considerable force each time the shuttle is to be thrown to theopposite shuttle box.

The box is also provided with fixed front and rear walls 32 and 34,respectively located on either side of the box opening. The generallyrectangular opening within the box is dimensioned to accommodate theshuttle although somewhat longer than the shuttle. Associated with thefixed wall 34 is a movable member 36 known as the binder and pivotedabout a pin 38 at the end of the wall 34. The binder 36 is provided`with a working leather covered face 40 which is adapted to move towardsa cooperating leather covered face on wall 32. The binder serves tofrictionally engage the sides of the shuttle and in cooperation with thefixed wall 32 to bring the shuttle to a halt.

Movement of the binder 36 is by means of an arm 42 fixed to a controlrod 44 extending parallel to the lay. The arm 42 is provided with anadjustable stop 46 which bears against the outer surface of the binder36. The control rod 44 is pivotally mounted to the lay by suitablebearings (not shown) and is angularly deflected about its longitudinalaxis by means of a solenoid 48 drivingly connected by a rod 50 to acrank 52 fixed to the control rod 44. The solenoid 48 is of the rotarytype having a crank arm 54 connected to the lower end of the rod 50. Itwill be understood that each time the solenoid 48 is actuated, the rod50 will be pulled downwardly to bias the rod 44 and the arm 42 to theright as viewed in FIG. l, forcing the binder into the shuttle box. Theupper end of the connecting rod 50 is provided with an adjustment nut56, a lock nut 58 and a compression element 60, allowing a certainamount of play between the connecting rod and the crank 52. Thus whenthe shuttle is in the box, the play allows the actuating mechanism tomove through a certain distance before the inertia load of the crank andits attachments are met. The compression element 60 may be aconventional helical spring or an annular resilient bushing to allow theactuating mechanism to continue traveling when actuated and apply agradually increasing force to the binder.

Also carried by the control rod 44 is a latch 62 which in its loweredposition is adapted to engage an abutment 64 which stops the motion ofthe lay and in its raised position will clear the abutment 64 thusmaintaining continued operation of the loom. It will be understood thatif the shuttle is in the box the movement of the binder 36 will belimited and the latch 62 will not be dropped low enough to engage theabutment 64 but rather lwill clear the abutment so that the operation ofthe loom will continue. In the event that the shuttle for some reasonshould not enter the box, the binder 36 would oter no resistance to thearm 42 with the result that rod 44 will be rotated more than normal andthrough an arc sufficient to drop the latch 62 down to engage theabutment 64, thus stopping the loom. In practice, the control rod 44 isspringloaded as by a pre-loaded spring 66 so as to urge the rod normallycounterclockwise as viewed in FIG. l.

The solenoid 48 is under the control of a shuttle detecting andpositioning system which includes a light source such as a bulb 68producing a photo beam 72 across the shuttle box entrance against aphoto-electric detecting device 70 on the opposite side of the box.Assuming the shuttle is moving in its proper fashion it will interruptthe beam 72 as it enters the shuttle box. This will produce a signalfrom the photo-electric device 70 which in turn will initiate a timedelay of `a very short duration, after which the solenoid 48 will beactuated. The time delay is sufiicient to permit the shuttle to moveinto the box before the binder is actuated. The timing is such that theshuttle will be brought to a full stop at a predetermined, precise andrepeatable position within the shuttle box without rebounding. It willbe understood that a photo-electric sensor is located at the entrance ofeach shuttle box and the same solenoid 48 through the control rod 44actuates each binder simultaneously.

Referring now to FIG. 2 there is shown a simplified schematic diagram ofthe control circuitry associ- `ated with the shuttle box control system.In FIG. 2 two photo-electric eye systems are shown with the bulb 68, andthe sensor 70 on the left-hand side of the loom and a bulb 74 and asensor 76 on the right-hand side of the loom at each entrance of theshuttle boxes. A shuttle is indicated by the reference character 78 andit will be understood that the shuttle is propelled back and forthbetween the photo-electric sensor system by means of the picker sticks28 and 28. The two photo-electric sensors 70 and 76 are connected byleads 80 and 82 through amplifiers 84 and 86 to a gate 88. The output ofthe gate is to a time delay unit 90 which in turn is connected to thesolenoid 48. It will be understood that a signal will be generated eachtime the shuttle 78 crosses the beam 72 or 72 and when a pair of signalsare produced by the shuttle 78 leaving one shuttle box and enteringanother, these two signals will indicate that the shuttle hassuccessfully traversed the shed. The two signals will thus appear `atthe gate 88 to provide an output to the time delay 90, 'which in turnwill actuate the solenoid 48 causing the binder to grab the shuttle andbring it to a stop.

In FIG. 2 the time delay 90 is of a fixed duration. In FIG. 3 there isshown a schematic diagram for a variable time delay. The FIG. 3 systemaffords means for varying the time at which the braking solenoid isenergized as a function of the speed of the shuttle in crossing theshed. The faster the shuttle is traveling the sooner the brake will beactuated. The reverse is also true in that if the shuttle were travelingslowly there would be a longer delay and less braking action. Thecircuit of the variable control means is generally organized about areversible counter 92 which is started to count upwards as soon as theshuttle 78 interrupts the photo cell at the exit of the box from whichit is being propelled and continues to count upwards as the shuttletraverses the shed. The counter is stopped and reversed in directionwhen the shuttle interrupts the second photo cell in the receivingshuttle box. After reversal takes place, the counter commences to countdownward at a much faster rate and, when it reaches the same number atwhich it originally started, the braking solenoid 48 is energized. Thefaster the shuttle is moving the fewer counts are accumulated by thecounter and therefore the less time is required to run the counter downagain before energizing the brake. The brake is therefore actuatedsooner for fast shuttles than for slow shuttles. The relative delay maybe changed by adjusting either of the counting rates.

Referring now to FIG. 3 there is shown a further feature of theinvention. In FIG. 4 `a piston or solenoid 100 is mounted to the loomframe and is provided with a driving piston 102 adapted, when extended,to engage a member 104. The member 104 is connected by means of a rod106 to a crank 108 on the lower end of a manual control arm 110. The arm110 is fixed to a control rod 112 which actuates a clutch and brake 114in the loom drive mechanism. The function of the solenoid is toautomatically disengage the clutch and engage the brake in the event ofa malfunction. The solenoid 100 is timed to disengage the clutch beforethe lay 12 is brought to a halt by means of the latch 62 engaging the`abutment 64 as shown in FIG. 1. By disengaging the clutch before thelay stopping mechanism is engaged the loom may be operated at a higherspeed without the attendant higher kinetic energy being concentrated onone stopping mechanism. By disengaging the clutch first before stoppingthe lay a substantial portion of the kinetic energy is separated fromthe lay so that it may be brought to a stop much more easily and withoutdamage. The clutch remains subject to manual control by means of the arm110.

Referring now more particularly to FIG. there is shown a novel threaddepletion detector. As mentioned previously, the shuttle 78 carries areplaceable bobbin 116 which is wound about with a supply of fillerthread 118 which unravels from the bobbin on each pick, leaving a trailbehind the shuttle. In order to provide a continuous weaving operationthe bobbin 116, when its supply of filler thread is almost depleted, isreplaced with a full bobbin by a doffing mechanism. The dong mechanismknocks out the nearly empty bobbin from the shuttle and replaces it witha full bobbin. The dofiing mechanism heretofore has been actuated bymeans of a mechanical device which probes against the bobbin each timeit enters the shuttle box. As long as there is a supply of thread on thebobbin the probe merely pushes against it and retracts. When the yarndepletes past a certain point the probe strikes against the bobbinsurface and is biased in such a manner as to mechanically actuate thedoing mechanism. This technique is unsatisfactory for a number ofreasons including an objectionable marking of the weft thread by thecontacting probe, which marking shows up on the finished fabric, and a`substantial waste in that the actuating mechanism is usually initiatedWhile there is still a fair supply of yarn on the bobbin.

These problems are overcome by the system in FIG. 5 which features aphoto-detector employed to monitor the supply of weft thread on thebobbin. As shown, a light source 120 directs a beam 122 `against thebobbin 116 near the base thereof. A photo-detector 124is located to pickup the refiected beam 122. The light source 120 and the photo-detector124 are located on the side of the loom and are timed to scan the bobbinthread supply each time the shuttle is brought to a stop by the brake.As is usually the case, the filer thread 118 is white and the beam 122will be reflected back to the detector 124 as long as there is a supplyof filler thread on the bobbin. The bobbin is provided with a dark,preferably black, annular band 126 near the base of the bobbin and itwill be understood as the thread unwinds the dark band will be exposedand the beam 122 which is aimed at the base of the bobbin will no longerreflect. This will cut off the signal from the photo-detector 124indicating that the yarn is almost depleted and will actuate the doffingmechanism to bring in another bobbin with a fresh supply of thread.

The thread depletion detecting system is operated in conjunction with atiming arrangement whereby the thread is inspected during a certainperiod in the time cycle of the loom. This protects against falseindications at all other times. The detector is used in conjunction withcontrolling means for initiating the dofiing a-ction at the proper timeafter detection has been accomplished. The timing arrangement includes atiming disc 128 which is driven by the loom main drive shaft 130. Thetiming disc is formed with a number of predetermined apertures includingan aperture 132 adapted to pass a beam 134 from a light source 136 to aphoto-detector 138, The output of detector 138 is through an amplifier140 to an amplifier 142. Similarly the output of photo-detector 124 isthrough an amplifier 144 to the same amplifier 142. Thus, depending uponthe character of the signal from the detector 124, the solenoid 146 willbe energized to actuate the doffing mechanism generally indicated byreference character 148.

In FIGS. 6, 7 and 8 there are shown modifications of the threaddepletion detector. In the FIG. 6 embodiment a bobbin 116 is formed witha reduced portion 150' at its base, the reduced portion forming conicalfaces 152 and 154.

Formed about the reduced portion 150 is a transparent filler 156 theouter cylindrical surface of which is flush with the remaining portionof the bobbin. The transparent filler provides an optical path betweenthe opposing conical faces which are naturally reflective. The yarn 118is wound about the bobbin in the usual fashion and depletes from rightto left as viewed in FIG. 6. Light source 120 is directed at the base ofthe bobbin towards the conical face 152. The detector 124 is locatedopposite the conical face 154. As the yarn unwinds, the conical face 152will be uncovered to admit the light from source 120 to reflect off face152 and against face 154 to be directed against the detector 124'. This,of course, will initiate the doffing mechanism.

In the FIG. 7 embodiment a bobbin 116 is formed with a central passage158 in its base terminating at a conical face 160 within a transparentcore 162. The core 162 is of the same diameter as the bobbin shank andis adapted to register with a photo-detector 124 located radiallyoutwards from the core. A light source 120 is located in position todirect a beam of light against an angularly mounted reflective plate 164carried by the shuttle. The beam of light travels up through the passage158 striking the conical face 160 to be directed radially outwards. Asthe thread unwinds the core 162 will be uncovered and the beam of lightwill impinge upon the photo-electric device 124 to actuate the doffer.

In the FIG. 8 embodiment a bobbin 116'" carries a tuning fork 166 thearms of which extend lengthwise of the bobbin towards the left as veiwedin FIG. 8. The outer surface of the tuning fork arms normally extendslightly out from the face of the bobbin and when thread is Wound aboutthe bobbin it binds against the tuning fork arms. A high frequency soundgenerator 168 is located to direct, on signal, a sonic pulse against thetuning fork each time the shuttle with its bobbin stops in position atthe shuttle box. If there is still an ample supply of thread on thebobbin the thread will immediately dampen the signal, whereas when thethread supply is depleted the tuning fork will resonate and thisresonance will be picked by a transducer 170 to actuate the doflingmechanism.

Referring now to FIG. 9 of the drawings there is illustrated an improveddevice for detecting tension and/ or breakage of the filler thread. Thedevice is generally organized about a bracket 172 and the device may bemounted as a single unit at the center of the lay or the device may beemployed in pairs, one at each end of the lay. In any event the bracket172 of the illustrated device is mounted firmly to the lay below theshed and carries a rotary solenoid 174 having a crank arm 176 adapted toengage a finger 178. The finger 178 extends out from a hub 180 on theend of a spring-loaded shaft 182 mounted coaxially with the solenoid onan opposite wall of the bracket. The shaft 182 is normally urgedcounterclockwise as viewed in FIG. 9 by means of spring 184. The hub 180has fixed thereto thread sensing fingers 186 mounted in spaced parallelrelation to one another. Mounted also to the hub 180 is a shutter 188adapted to move between a light source 190 and a photo-electric detector192. The finger and shutter assembly have very low inertia being of verylight construction as compared to other types of thread detectingmechanisms. The fingers 186 are urged normally downwards by means of thespring 184 and the preloading force on the fingers is relatively largeas compared with the inertia to prevent bounding of the fingers andshutter. The Shutter is disposed as to expose light to the detector whenan unbroken and properly tensioned filler thread is laid down on eachpass of the shuttle.

The device operates as follows. When the shuttle is fired from one ofthe shuttle boxes a signal is sent to the solenoid 174 energizing it andflipping the crank 176 along with the fingers 186 upwardly through thewarp threads to be clear of the shuttle as it flies past. When theshuttle has passed, the solenoid is de-energized and the spring 184 willbias the fingers 186 downwardly against the filler thread left by theshuttle. Assuming that the filler thread is unbroken it will havesufficient tension to keep the fingers 186 from passing through thelower layer of warp threads and will hold it substantially in theposition shown in FIG. 9 with the shutter 188 clear Of the beam betweenthe light source and the detector 192. The signal generated by thedetector will indicate an unbroken properly tensioned yarn. If the yarnis broken or not properly tensioned the filler will not have sufiicienttension to prevent the fingers 186 from dropping down and this willcause the shutter 188 to move between the light source 190 and detector192. A dark indication will thus be present when the yarn is broken orpoorly tensioned. The configuration is fail safe in that if the lightsource should fail for any reason, it will give the same indication as abroken thread, stopping the loom for -correction of the malfunction.

The device illustrated in FIG. 9 is particularly suited for centermounting of the lay of the loom although it will e understood that sucha device may be mounted on either end of the lay at the ends of theshed. Also in place of the solenoid actuating mechanism a conventionalactuating means may be employed where the unit is to be located adjacentthe shuttle boxes. In such an installation opposing fingers are mountedon the opposite side of the weft and the pivoted finger will try tointerlace with the fixed fingers each time the thread is laid down. Ashutter and photo-cell system would be maintained and in event of abroken thread or poor tension a signal will be generated to stop theloom.

Regardless of the type of mounting arrangement either singly or one onboth sides, signals from the photo-cells are correlated with timingsignals derived from the timing disc 128 coupled to the loom shaft to bedescribed more fully below. The signal from the detector photo-cell 192is examined only during a short interval corresponding to the time thatthe filling thread should be in engagement with the sensing fingers.Logic and control means consisting of electronic circuits are used inthe preferred ernbodiment to energize solenoids which operate thestopping mechanism when required. The above device is of simpleconstruction highly accurate in its detection and is substantiallyimmune to wear since there are a few moving parts which might wear orget out of adjustment.

Referring now to FIG. l0 there is disclosed a novel .system forcontrolling the shedding motion of the loom 1n a manner adapted toreduce yarn Ibreakage while increasing the speed capability of loom. Ina conventional loom the warp threads are moved in the shedding action bymeans of harnesses which are vertically reciprocated by cams, the camsfollowers being linked to the harnesses to provide a variety of motions.The cam arrangement iS not particularly smooth and results in ratherhigh frequency of warp thread breakage due to the jerky motion. Afurther disadvantage is that there is no convenient lmeans for adjustingthe timing of the opening and closing of the shed or adjusting theduration of the time period during which the opening or closing istaking place.

With the present improved shedding system a smoother motion of theharnesses is obtained thus decreasing the breakage of the warp yarns andincreasing efficiency. The system is also easily adjusted as to timingand duration of the opening and closing of the shed.

As shown in FIG. l0 the system includes pneumatic or hydraulic cylinders194 and 196 mounted upright to the loom frame and having pistons 198 and200 drivingly connected to harnesses 202 and 204. Only two cylinders areshown for the sake of simplicity and are used when weaving a plain weavefabric. For more fancy weaves additional harnesses and cylinders areemployed. The upper ends of the harnesses are connected in the commonfashion by straps wrapped about pulleys so the harnesses operate inunison. An air valve 206 actuated by a solenoid 208, controls admissionof air to each cylinder. Each cylinder is provided with a two-way airvalve 209 which admits air under pressure to the top of the cylinder orvents that end of the cylinder. The opposite end of the cylinder isprovided with a vent 211 which regulates the flow of air from the bottomend of the cylinder when air under pressure is admitted to the top ofthe cylinder, moving its harness down or which vents regulate theadmission of atmospheric air to the bottom of the cylinder when itspiston is pulled upwards by the rising of its harness, the power for therising of the harness being furnished by the opposite harness movingdownward. Separate vents and corresponding restrictive oriiices may beprovided when it is required to maintain the proper speed of motion andtension in the linkage between harnesses in separate directions. Otherarrangements for venting and switching the air supply may be used toadvantage.

The air control solenoid 206 is actuated by the rotary timing disc 128,the operation of which will be described more fully below. The timingdisc is formed with an arcuate slot 216 adapted to register with a lightsource and photo-detectors 212 and 214 respectively. The slot issubstantially 180 degrees of the entire circle representing two picks ofthe loom. The photo-cell output is amplified to a level sufficient toenergize the solenoid-operated valves controlling the air ow to thecylinders.

Referring now to FIG. 11 there is shown a somewhat schematic diagram ofthe logic circuit employed to operate the various portions of the loomdescribed above. Generally the logic circuit is a timing arrangementadapted to provide proper sequential operation of the loom and itscomponents. The timing arrangement is basically under the control of thetiming disc 128 which is slotted with a plurality of arcuate slotsadapted to pass light from a source 136 to a bank of photo-detectors ina pre-determined sequence and for the pre-determined periods. The bankof photo-detectors includes detector 214 which controls the operation ofthe harnesses as described in FIG. l0. Detector 138 is employed inconjunction with Ithe thread depletion unit described in connection withFIG. and operating in cooperation with photo-detector 124 for examiningthe supply of yarn on the bobbin and for actuating the doiiing mechanismwhen required.

`Detector 220 in the bank serves to control the timing action of thebroken thread detector and operates in cooperation with photo-detector192 and where two broken thread detectors are employed a secondphoto-detector 192' is employed. In any event, the timing signals fromdetector 220 are fed into an amplifier 222 through an extender diode224. Ampliiier 222 also receives inputs from photo-detectors 192 and192' through ampliliers 226 and 226. The output of amplifier 222 isthrough a Hip-flop 228 out to the solenoid 100 which stops the loom. Itwill be understood that a stop signal will be generated only when apositive signal is generated by the broken thread detector.

The shuttle box control system includes detector 230 in the bank whichcooperates with photo-detector 70 and 76 located at the entrances ofeach shuttle box. The timing disc 128 makes a single revolution for eachcomplete cycle of the loom, that is the shuttle having been propelledfrom both right and left shuttle boxes with two picks of ller threadhaving been laid down across the warp threads. The detector 138 providestiming signals for the shuttle box braking system through the solenoid48. This channel is provided with a pair of arcuate slots on the timingdevice one of which operates in conjunction with light source 136 andphoto-cell 230 which controls the solenoid 48. The second of the arcuateslots operates in conjunction with a light source 232 and aphoto-detector 234 for use in stopping the loom by means of the pistonor solenoid 100 when the shuttle is not in the proper position. Slotsare formed in the disc along the appropriate channel and positioned sothat photo-detector 230 receives light for a short period of time thebeginning of which occurs not earlier than the latest time the' shuttleis normally fully positioned in the appropriate shuttle box, and the endof which occurs not later than the earliest time in which the shuttlecommences to be propelled from the appropriate shuttle box.

The signals from photo-detectors 70 and 76 and from detector 230 are'fed respectively to elec-tronic amplifying land limiting meansconsisting of limiting 'amplifiers 84, 86 and 236 respectively, thelatter being coupled to ipops 238 and 240, gate 242, time delay device244, diferential means 246, ip-fiop 248, power ampliiier 250 andsolenoid 48. Other slots cut `in the disc 128 are positioned so thatphoto-detector 234 receives la light for a period of time the beginningof which occurs not earlier than `the latest Atime the shuttle can .beproperly received and fully positioned in its appropriate shuttle tboxand not later than t'he earliest 'time 'in which the shuttle ispropelled from the appnopriate box. The signal from photodetectors 70and 76 and 234 are fed respectively to ampliers 84 land 86.

`Having thus ydescribed the invention, what we claim and desire toobtain by Letters Patent of the United States is:

1. In ian automatic loom having a shuttle box disposed a-t each sidethereof `for receiving and guiding a shuttle propel-led between saidshuttle boxes, and each box lhaving 'braking means lfor stopping saidshuttle within said box, a control system for actuating said brakingmeans, comprising (-a) shuttle detecting means adapted to sense movementof said shuttle past la point :between said #boxes and 'to generatesignals relative thereto,

('b) electronic time delay means operatively connected to said detectingmeans and lactuated by signals ttrom said detecting means, and,

:(c) automatic bnake actuating lmeans including 'a solenoid responsiveto said time delay means and adapted to factuate said braking means tostop said shuttle at the end of a delay period.

2. A control system according to claim 1 wherein said shuttle detectingmeans includes a light source and a pho'todetecting device disposed onopposite sides of the path of travel yof said shuttle.

3. A ycontrol Isystem according to claim 2 wherein a light source andphoto-detecting device are located at the entrance of each shuttle box.

4. A control system according eto claim -1 wherein said time delay meansis variable and respons-ive to the speed of said shuttle.

5. A cont-rol ysystem Iaccording to claim 1 wherein said lbnakeactua-ting means includes a solenoid drivingly connected directly tosaid lbraking means.

6. A control system according to lclaim `4 Iwherein sa'id time delaymeans includes a reversible electronic counter adapted to count in `onedirection at a predetermined rate upon a rst signal from said shuttledetecting means :and in vreverse direction at another rate upon a secondsignal from said shuttle detec-ting means.

`7. A control system according to 'claim 4 wherein said time delay meansincludes a rever-sible electronic counter, a high speed clock Iand a lowspeed clock adapted to provide signals to said counter 'and logic meansconnected to said `s'huttle detecting means to said clocks `and to saidcounter whereby said counter will count slowly in one direc-tion from astart-ing condition upon detection of the shuttle leaving yone b'ox andcount rapidly in the opposite direction upon detection of the shuttleentering the opposite box, said -counter being adapted to energize saidsolenoid upon sa'id counter returning to its starting condition.

8. A control system according to claim 1 including a timing wheeld-riven lby said loom and adapted 'to provide timing signals Ito saidcontrol system.

9. A control system according Ito claim 8 including 11 12 solenoid4operated 100m stopping means lresponsive t0 13,144,883 8/ 1964 Short139-55 signals 4from said 4timing lWheel and 'adapted to stop Sa'id3,298,401 1/ 1967 Stutz 139-371 loom `in che event off a detectedmalfunction. 3,358,1717 12/ 1967 Schooley 139-341 References Cited 5FOREIGN PATENTS UNITED STATES PATENTS 1,296,090 5/ 1962 France. 4/1933Means 139 55 1,359,888 3/1964 France. 2/1935 [Hopewell 139-187 600,3307/1934 Germany- 3/1941 Meltcalf. 834,527 3/1952 Glllafly. 8/1947 Hindle139 55 1() 933,704 2/1965 Great Britain. 2 i 'f 3 2 .1

ggg/Ech 1939 73376 JAMES KEE CHI, Primary Examiner. 9/1950 Dion et al.139273.1 12/1962 cmg @t a1. 139-336 US O1' X'R' 3/1964 Pfam-wauw 139-341X 15 88-14; 139-336, 341

